Fire-tube-boiler blower.



E, C. HAFER.

FIRE TUBE BOILER BLOWER.

APPLICATION FILED JAN. 6. I917.

1,30 1. ,255. Patented Apr. 22, 1919.

2 SHEETSSHEET l.

29 2/ 2. /4 T a- I 1 HAW-M1301 Edward Oflafer E. C. HAFER.

FIRE TUBE BOILER BLOWER. I APPLICATION FILED JAN. 5 1917;

2 SHEETSSHEET 2- l I i gmvamtoz g a M! 1 1% mm mm mu EdwamZ Gfla/er EDWARD C. HAFER, OF GHAMBERSBURG, PENNSYLVANIA.

FIRE-TUBE-BOILER BLOWER.

Specification of Letters Patent.

Patented Apr. 22, 1919.

Application filed January 6, 1917. Serial No. 140,965.

To all whom it may concern Be it known that I, EDWARD C. HArnn, a citizen of the United States, residing at Chambersburg, in the county of Franklin and State of Pennsylvania, have invented certain new and useful Improvements in Fire-Tube-Boiler Blowers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in blower attachments for furnaces, and more particularly to the general type indicated in my U. S. Patent, No. 1,151,177, dated August 24, 1915.

The two primary objects in view are to prevent excessive back-firing and to obviate the presence of obstructions tending to interfere with repairs to fire tubes.

Other and more detail objects will hereinafter in part become apparent and in part be stated in the following further disclosure of the invention, which invention comprises certain novel constructions, combinations and arrangements of parts as will subsequentlv be rendered clear and later specifically pointed out in the claims.

In the accompanying drawings,-

Figure 1 is a longitudinal, vertical section through a boiler furnace, having applied thereto an embodiment of the invention, parts being seen in elevation.

Fig. 2 is a front elevation of the same, parts being broken away.

Fig. 3 is an enlarged detail fragmentary elevation of parts seen in Fig. 2.

Fig. 1 is a vertical cross section taken on the plane indicated by line ie-4t of Fig. 3.

Fig. 5 is an enlarged, detail, side elevation of a fragment of a modified form of communicating pipe showing a slip-joint, parts being broken away for disclosing the gland of the joint.

Fig. 6 is a view similar to Fig. 3 of an embodiment of the invention including the plane indicated by line 1010 of Fig. 7.

Fig. 11 is an enlarged, detail sectional view through one of the nozzles detached.

The desirability of the use of a blower is well recognized because of the interference with the draft of deposits in fire tubes, which deposits can be removed only with the greatest difficulty by any known mechanical means, whereas, when the deposits are sufficiently frequently removed by the use of steam blasts, their removal may be accomplished quickly, easily and with practically no expense, but blowers of the type required for accomplishing this work have been found objectionable because it is impractical with the usual type of boiler to deliver the blast in the direction of draft. To do this would require that the blower mechanism should be located at the rear of the boiler, where the blast is so excessive that theblast for removing solids therefrom, the

back draft created is sufficient to blow back to and across the body of fire on the grate, which results in the projection of a flame out through the furnace doorway. If the furnace doors are not open, they are frequently blown open, and I have observed occasions when the flame projected through a fire-door-way has been of sufficient volume and intensity to reach to the top of the boiler. This is disconcerting and frequently actually injurious to the operator who must stand adjacent the front end of the boiler to control the delivery of the blast. I have, by successful tests, ascertained that by reducing the number of fire tubes subjected to blast at one time, this disastrons result can be avoided. If, for example, one-third of the total number of tubes is blown at one time, the product of the back blast upon being ejected from the rear ends of the tubes will in part drop to the ash pit in the rear of the bridge wall, and in part be carried around into the tubes through which the normal draft is continuing and be carried with such draft on through the flues and out the stack' Thus, the effect of the back blast on the fire is largely obviated and all danger to the operator is entirely eliminated.

To accomplish the best results in the care of the boiler, it is desirable that the tubes should be blown out at relatively frequent intervals, which gives rise to the desirability of a permanently mounted blowing apparatus such as that shown in my above identified patent and such as is disclosed in this application, but with such permanentlymounted apparatus in the line of the several fire tubes, difficulty is experienced in gaining access to the tubes for repairing the ends thereof or otherwise operating upon. the tubes. To overcome this difficulty, I have provided a structural arrangement whereby the blower may be maintained permanently mounted in a definite relation to the fire tubes, but is capable in part or in whole of being temporarily shifted, with no difficulty whatever, away from an operative position and back to such position, whereby free access may be easily had to the fire tubes.

Referring to the accompanying drawings by numerals, 1 indicates an ordinary boiler furnace in which is mounted the usual fire tube boiler 2, having the usual fire tubes 3, 3. Above the fire doors, the furnace front is provided with doors 4, 1, enabling access to the front end of the boiler, which doors, when opened, leave the exposed door-way, uncovering practically the entire end of the boiler 2.

Axially alined above the uppermost row of fire tubes 3, as clearly seen in Fig. 2, are arranged tubular headers 5, 5, each closed at each end, and each of a length suflicient to extend above a less number than one-half of the total number of fire tubes. Each of the headers 5 is sustained in'a bracket 7, best i seen in Figs. 3 and 4, which brackets are fixed to the front end of the boiler and are each provided with set screws 8, disposed to clamp the respective header 5 in position. Depending from each header 5 are tubes 9, 9, extending across the open front ends of the fire tubes 3, there being a sufficient number of tubes 9 and of sufficient length to extend across the open ends of all of the fire tubes. Each tube 9 is provided with a discharge nipple 10 of any preferable or appropriate type, such, for example, as that seen in Fig. 11, or as shown in my above identified patent, positioned and directed for delivering a discharge axially into the adjacent tube 3. Each of the headers 5 is supplied with blast producing fluid, such as steam or compressed air. The compressed air connections will be later described. The fluid is supplied through pipe 11, there being one pipe 11 for each header, and all of the pipes 11 extending to and communicating with the valve casing 12 of a valve 12, which is a distributing valve for all of the pipes 11 of the type seen in my above identified patent, but improved thereover as hereinafter pointed out. The valve 12 is designed and adapted for delivering a blast successively and independently to the several pipes 11, the pressure fluid being supplied through a pipe 13 to the valve 12 from the steam dome 14 of the boiler 2.

The pipe 13 communicates through the side walls of the casing 12 to the interior of the casing, while the several pipes 11 communicate through the base or back wall of the casing 12 with the interior thereof, said communication being controlled by the valve 12, which is of the disk type and rests against the back wall of the valve casing 12 for closing the ends of the several pipes 11. A single port 11 is formed in the valve 12 so as to provide a means of establishing communication successively between that part of the casing 12 with which pipe 18 communicates and the several pipes 11. The valve 12 is provided with an outstanding stem extending through the casing 12 and carries an operating handle 12, by which the valve is adapted to be rotated for bringing the port 11 successively into register with the pipes 11. Since the pressure of fluid supply through pipe 13 is exerted on the outer face of valve 12, in a direction toward the inner wall or base of valve casing 12, the said valve 12 is held against the said wall with such frictional engagement as to cause a very appreciable resistance to rota tion of the valve, especially if the valve is made with its inner face fiat so as to lie in substantially contiguous contact with the base of the casing 12. To relieve this excessive friction, I have formed the inner face of valve 12 with a hollowed-out portion 12, leaving only a ring 12 about the edge of the valve, and a ring 12 about the edge or port 11' outstanding beyond the recessed face portion of valve 12. It is, therefore, only the exposed edges of the rings 12 and 12 which frictionally engage the base of the valve casing 12.

Each pipe 11 is provided with an ordinary union 15 for facility of connecting up with the valve casing 12, and each pipe is connected with its respective header 5 by a plug valve 16, rigidly carried by the respective pipe and journaled in a globular casing 5, detachably fixed to and upstanding from the respective header 5, as best seen in Fig. 3. Each header 5 is thus adapted to be swun from the position seen in Fig. 4: in full lines about the axis of the valve 16 to the position indicated in dotted lines in said Fig. 1, it being understood, of course that the set screws 8 will be withdrawn sufficiently for allowing the swing of the header in moving about the axis of the valve 16.

A valve 20 is arranged in pipe 13 for cutting off communication with casing 12 when desired, the valve 20 being preferably adjacent casing 12. A valve 21 is also arranged in the length of pipe 13, spaced from the steamdome 14 for cutting off the supply of steam to the pipe 13. Between the valve 21 and the steam dome, a branch pipe 22 leads from pipe 13 down to a steam turbine 23,- which Operates air pumps 24, the latter communicating through pipes 25 with a supply tank 26 for compressed air. A valve 27 controls the discharge of steam through pipe 22. A pipe 28 leads from tank 26 to the pipe 13 beyond the valve 21, and valves 29 are arranged in the length of pipe 28v for enabling the control of delivery of compressed air to the pipe 13. The operation of the blower will, of course,be the same whether steam or compressed air is supplied, and the supplying of either will be governed by the position of the respective valves 21 and 29. An exhaust pipe leads from the turbine 23 to the ash pit of the furnace 1, and a drain pipe 31 leads from the lowermost portion of the valve casing 12 to the said ash pit for discharge of water of condensation.

A branch pipe 32 leads from the forward portion of pipe 13 through the furnace front and is controlled by a valve 33. The pipe 32 communicates with a header 34, which is arched and disposed across the upper portion of the boiler 1. The pipe 32 then extends beyond the arched header 34 and communicates with a similar header 35, spaced forwardly of the steam dome 14 and the pipe 32 is extended beyond the header 35 and curved about the dome 14 to and communicates with a header 36 similar to header 34 and arranged at the rear of the dome 14. Each of the leaders 34, 35 and 36 is provided with nozzles 37 for delivering streams of fluid under pressure longitudinally of the boiler for cleaning from the upper portion thereof such foreign substances as may become deposited thereon. Between each two of the headers 34, 35 and 36, the pipe 32 is provided with a union 38 for facilitating assembling and mounting of the parts.

In operation, when it is desired to clean out the tubes, the valve 12 is set to deliver a blast to one of the headers 5, and the steam is delivered from the respective header 5 through its pipe 9 and their nipples 10 to the several fire tubes 3 supplied from the re-- spective header. The blast is maintained for thetime required for thoroughly cleansing the tubes, and the product of the discharge which is directed counter to the draft of the furnace is in part returned through the other tubes not affected by the steam blast, the heavier solids falling into the rear ash pit. When the first set of fire tubes has been thoroughly cleaned, the valve 12 is turned for closing the pipe 11 of the first port 11 approximately midway between two a of the pipes 11, so as to cut off communication between pipe 13 and the several pipes 11. By this construction, the number of tubes cleaned from a given header may vary according to the size of header provided,

but in no instance is it desirable to have any one header of sufficient size to supply a maj ority of the total number of fire tubes. Another advantage from the provision of sepa rate and distinct headers arises from the fact that if a particular fire tube is to be repaired or otherwise operated upon, only one header needs to be shifted for that pur pose, and all of the others with their pendent tubes can remain untouched.

When it becomes desirable to have access to one or more of the fire tubes, the operator merely grasps one or more of the pipes 9 and swing the same outward and upward, the lower ends of the pipes swinging out through the door-way of doors 4 and the pipes 9 being moved until they assume an upstanding position such as indicated in dotted lines in Fig. 4. The frictional engagement between the casing 5' and valve 16 will usually be sufficient to sustain the pipes 9 in this elevated position, but if, at any time, said friction is not suflicient for this purpose, the parts may be tied in the elevated position or otherwise supported. Vhile the parts are so elevated, the operator has free access to the fire tube until his work is completed; whereupon he merely grasps the upstanding tubes and swings them down to their pendent position, which brings the parts back to the osition indicated in full lines in Fig. 4, anc the set screws are again tightened up. It is preferable, of course, to have the set screws 8 set against the respective header 5, so as to hold the same against movement.

It will, of course, be understood that the above described embodiment of the inven tion is only one of a number which may be satisfactorily and effectively employed As indicating one other eflicient form, a slightly varied structure is illustrated in Figs. 5, 6 and 7 in which the header 5 with its pendent tubes 9' are the same in structure, location and function as the header 5, and its tubes 9, above described. From the header 5 outstands the globular casing 18, in which is journaled the valve 19, which valve is fixed to the fluid'supply pipe 11. A portion of each ipe 11 e'Xtends vertically upward from t e valve 19 and thence to one side to the controlling valve, not illustrated. In the vertical portion of each pipe 11 is arof the way ranged the slip joint 17 to compensate for longitudinal thrust of the lower portion of the pipe incident to the movement of the valve 19, whereby the header 5 is permitted to rotate on its longitudinal axis while remaining in its supporting brackets 7 In the course of this rotation, there will be a slight lateral shifting of the lower portion of the respective pipe 11, which will be accommodated by a slight springing of the whole length of the pipe and a giving of the slip joint. The detail construction of the slip joint may be varied at will, a very effective embodiment being illustrated in detail in Fig. 5, wherein the joint is seen as consisting of the cylinder 17, having a gland 17 through which extends a tubular slide 17. The slide 17 is threaded to one portion of pipe 11*, and the cylinder 17 is threaded to the other portion thereof, whereby pipe 11 is adapted to be contracted and elongated as required in the course of rotation of the respective header 5 upon its longitudinal axis. The pipes 9 may thus be elevated out in substantially the same manner as described with respect to pipes 9, by merely being swung from their depending position upward to their elevated position. Each header 5", in the course of rotating incident to such upward swing of pipes 9', causes its valve 19 to move through an are past the vertical plane of the axis of header 5", so that any elfort to return the parts to their normal operative position after the pipes 9 have been elevated is resisted by vir tue of the fact that in moving back from itsinner position, the valve 19 thrusts the lower section of pipe 11 upward with a corresponding thrust of the tubular slide of the slip joint 17 This movement is, of course, resisted by the friction of the packing joint which is purposely maintained sufiicient to resist return rotation of header 5 merely under the weight of pipes 9. The said pipes will, therefore, remain in their elevated position until forced down against the resistance formed by the slip joint 17. In addition to this friction, the pipe 11 springs laterally upon header 5 being rotated, and the tension of the spring condition of the pipe 11 when the pipes 9' are elevated adds to the resistance against any pressure tending to lower pipes 9.

The amount of friction or tension required for maintainingthe pipes 9' in their elevate positions is only very slight, and the amount of actual springing of the pipes 11 is extremely small, so that there is no appreciable injury or undue strain suflered either by the pipes l1 or their joints incident to such springing action.

'What I claim is 1. In a fire tube boiler blower, the combination of a plurality of headers, a bracket for each header arranged at the front end of the boiler and adapted to support the headers therein when in operative position, discharge tubes carried by the headers, supply pipes hinged to the headers to permit in dependent movement thereof into and out of the brackets, and means for securing the headers in the brackets.

2. In a fire tube boiler blower, the combination, of a header revolubly mounted, a discharge pipe communicating with said header and adapted to be moved to and from an operative position incident to angular movement of the header, and a supply pipe communicating with the header and connected to be shifted during angular movement of the header from a position at one side of the plane of the axis of the header to. a position at the other side thereof.

3. In a fire tube boiler blower, the combination, of a header revolubly mounted, a discharge pipe communicating with said header and adapted to be moved to and from an operative position incident to angular movement of the header, a supply pipe communicating with the header and connected to be shifted during angular movement of the header from a position at one side of the plane of the axis of the header to a position at the other side thereof, and a bracket disposed to sustain the header.

4. In a fire tube boiler blower, the combination, of a header revolubly mounted, a discharge pipe communicating with said header and adapted to be moved to and from an operative position incident to angular movement of the header, a supply pipe communicating with the header and connected to be shifted during angular movement of the header from a position at one side of the plane of the axis of the header to a position at the other side thereof, a bracket disposed to sustain the header, and means for clamping the header in position in the bracket.

5. In a fire tube boiler blower, the combination of a header, discharge tubes leading therefrom, a supply pipe for the header,

a swiveled joint between the header and supply pipe spaced from the header and disposed to shift bodily with the angular movements of the header, and a slip joint in the length of the supply pipe arranged to compensate for the resulting longitudinal thrust incidenttothe shifting of the header.

In testimony whereof I aifix my signature in presence of two witnesses.

EDWARD G. HAFER.

Witnesses:

EDGAR M. KITOHIN, C. H.'FESLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

